In simple terms
The Mercator projection is a way of drawing the round Earth on a flat, rectangular map. The mapmaker Gerardus Mercator published it in 1569 to help sailors plan their routes.
It keeps directions true, which is why navigators valued it. The cost is size: the farther a place lies from the equator, the larger it looks.
How it works
No flat map can show a globe without stretching it somewhere. Mercator drew the lines of latitude and longitude as straight lines that cross at right angles. To make that grid work, the map stretches land more and more as it gets closer to the poles.
The payoff is that a straight line drawn anywhere on the map shows a true compass direction. A sailor could draw one line from port to port and follow a single steady heading. The price is that distances and areas near the poles are badly exaggerated.
Equal-area projections make the opposite trade. They show every country at its true relative size but bend shapes instead. Equal Earth, published in 2018 by cartographers working in the United States and Australia, is one example.
Why it matters
Maps shape how people picture the world. Because Mercator enlarges high-latitude lands, regions near the equator, including much of Africa, look small by comparison.
That concern has reached global politics. On 4 September 2026, the UN General Assembly voted 164 to 1, with 6 abstentions, for a resolution led by African countries that encourages equal-area maps such as Equal Earth. The resolution is not legally binding, and Mercator’s design is still widely used.
Where you’ll see it
- Wall maps and printed atlases.
- Charts for navigation at sea, the job it was designed for.
- News coverage of the 2026 UN “Correct the Map” resolution.
- Debates over which map schools should use, such as the 2017 decision by Boston Public Schools to switch to the Gall-Peters projection.
Example
The teacher hung an Equal Earth map beside a Mercator projection so students could see how much the older map inflates lands near the poles.
Often confused with
Gall-Peters projection. It is an equal-area map: sizes are true, but shapes in the tropics and near the poles look visibly stretched or squashed, the reverse of Mercator’s trade-off.
Key facts
- Gerardus Mercator published his world map in 1569 to help sailors navigate.2
- On a Mercator map, a straight line drawn anywhere shows a true direction, but distances and areas near the polar regions are grossly distorted.1
- The Equal Earth projection, an equal-area alternative by Bojan Šavrič, Tom Patterson and Bernhard Jenny, was published in August 2018.3
- On 4 September 2026 the UN General Assembly adopted the Correct the Map resolution by 164 votes to 1, with 6 abstentions. It encourages equal-area maps and is not legally binding.4
In the news
Quick checkWhat does the Mercator projection keep accurate, and what does it distort?Show answer
It keeps compass directions true but enlarges areas far from the equator.
Sources
- U.S. Geological Survey. How are different map projections used?. 21 February 2023 (updated) (accessed 11 September 2026)
- National Geographic Society. Gerardus Mercator. Undated (accessed 11 September 2026)
- Esri, ArcUser. Equal Earth Map Projection Meets Cartographic Needs and Desires. 21 February 2019 (accessed 11 September 2026)
- NPR. The U.N. backs a new world map showing Africa in its true relative size. 4 September 2026 (accessed 11 September 2026)
Editorially reviewed by Specialty Digest Editorial TeamLast reviewed September 11, 2026Researched and drafted with AI assistanceReport an issue